Having a better looking game is more important to get more people into Dota2 than new heroes, which players that haven't played any other ARTS care about, as there are enough to learn.

What new people? Last time I checked it's still in closed beta, and trying to bring in more people isn't no1 priority in a closed beta. HUD is, in a sense, cosmetic. Heroes are a core part of gameplay. You honestly think HUD changes are more important for learning dota than the actual heroes?